Microsoft 365 Admin
Each Microsoft 365 Account has an Admin username and password assigned. This is received when you signup for the Microsoft 365 service and it allows the Admin to oversee and manage all user accounts.
The Admin username is of the format admin@your-domain.onmicrosoft.com and the password can be reset by visiting https://admin.microsoft.com
The Admin area is where users and licenses are managed as well as policies such as Password reset protocol, 2FA (Two Factor Authentication) policies, DNS configuration and more.